Casing pipe classified by different materials

Casing Pipe Types:

Depending on the material used, casing pipe can be categorized as steel casing pipe and non-metallic casing pipe (PVC, fiberglass, and concrete). Their applications and performance in the oil industry vary significantly.

1. Steel Casing Pipe

Steel casing pipe can be further categorized by material, including carbon steel casing, alloy steel casing, and stainless steel casing.

Steel casing pipe is primarily used in the oil and gas industry due to its high strength and durability. Suitable for deep wells, high pressure, and high temperature environments (such as API standard steel grades J55, K55, N80, and P110), it can withstand formation pressure and the mechanical stresses experienced during drilling. Made from high-grade steel, it is often coated to prevent corrosion or reinforced with corrosion-resistant alloys (such as 13Cr, Super 13Cr, and duplex stainless steel). Steel casing pipe prices vary depending on the steel grade, coating, diameter, and thickness.

Typical applications: Conventional oil and gas wells, shale gas wells, ultra-deep wells, and high-temperature and high-pressure wells.

Seamless steel casing: Offers superior performance but higher cost.
Welded steel casing (ERW casing): Lower cost, but welds can become weak points.

2. Non-metallic Casing Pipe

1) PVC Casing Pipe
PVC (polyvinyl chloride) casing pipe is commonly used in water well drilling and construction. They are corrosion-resistant and lighter than steel pipe, making them easy to transport and install. They are also resistant to acids, alkalis, and salt spray, making them suitable for corrosive environments (such as saline aquifers and sewage treatment wells). PVC pipe is available in a variety of diameters and thicknesses, and its cost is generally determined by these factors, often resulting in lower prices than steel-cased pipe.

Disadvantages:
Low strength and poor resistance to high pressure/temperature (generally used in shallow wells or low-pressure environments).
Susceptible to UV degradation (requiring the addition of stabilizers).

Typical applications: Shallow water wells, monitoring wells, geothermal wells (low-temperature), and chemical waste injection wells.

2) Fiberglass Casing Pipe
Fiberglass casing pipe is known for its lightweight and corrosion-resistant properties. It is suitable for applications where neither steel nor PVC pipe is ideal, such as environments with strong acids, alkalis, and H₂S. It is generally lightweight and easy to install, and non-conductive, making it suitable for electrochemically sensitive environments. The price of fiberglass pipe varies depending on the type of glass fiber used and additional properties such as UV resistance.

Disadvantages:
Low crush resistance, requiring increased wall thickness or special design. The cost may be higher than that of ordinary steel casing pipe.

Typical applications: Corrosive oil and gas wells, seawater injection wells, and the chemical industry.

3) Concrete Casing Pipe
Concrete casing pipe is not a common type of casing, but it may be used in some specialized projects. Concrete casing is often used in large construction projects, including sewer and drainage systems. It offers high strength and durability, suitable for withstanding static ground pressure, but is less flexible than other types. The cost of concrete casing depends on the pipe size and strength requirements.

Disadvantages:
Low tensile and flexural strength: prone to brittle fracture, unsuitable for dynamic loads (such as drilling vibration and blowout shock).
Heavy weight: difficult to transport and install.
Permeability: Requires a waterproofing agent or coating to prevent fluid penetration.

Typical Applications: Underground structure reinforcement, drainage and sewage systems, water conservancy projects, or building foundations.

Other Non-Metallic Casing Pipes:
HDPE (High-Density Polyethylene) casing pipe: Used in low-temperature, low-pressure environments, such as shallow geothermal wells.
Composite casing pipe: Such as carbon fiber reinforced casing, used for specialized high-performance requirements, is extremely expensive.

Casing Pipe Purchasing Considerations:

1. Project Requirements
Ensure that the casing pipe meets the specific requirements of your project. Consider factors such as load-bearing capacity, corrosion resistance, and compatibility with other materials. Properly assessing these requirements will help you select the best casing for your application.

2. Bulk Purchasing and Bulk Purchases
If you need a large quantity of casing pipe, consider negotiating with the supplier for a better price. Bulk purchasing can also help streamline the purchasing process and ensure the consistency of the product you receive.

3. Supplier Reputation
Select a reputable casing pipe supplier or manufacturer that provides high-quality products and reliable customer service. Verify their certifications and review past customer reviews to ensure you receive a reliable product.

4. Installation and Maintenance
Consider the costs associated with installing and maintaining the casing pipe. Proper installation is crucial to extending the life of the pipe and reducing long-term maintenance costs. When evaluating the total cost of casing, consider the costs of installation, maintenance, and potential repairs.

5. Future Needs
Consider future needs or the possibility of expansion. If your project may require additional casing in the future, it may be helpful to establish a good relationship with a supplier who can fulfill future orders and offer consistent pricing.

Special Considerations:

Import Regulations: Some countries restrict the export of high-end steel (such as the US regulations on specific steel grades), requiring advance licensing.
Environmental Requirements: Some regions require materials to be recyclable or low-polluting (such as the EU RoHS Directive).
Localized procurement: If Saudi Aramco requires a "localization ratio" (e.g. 30%), it is necessary to coordinate with local suppliers.

Read more: Casing Pipe Application: from Borewell to Oil and Gas Well or API 5CT Steel Casing and Tubing Chart